XR16C2852_05 Datasheet, PDF (4/51 Pages) Exar Corporation – 2.97V TO 5.5V DUAL UART WITH 128-BYTE FIFOS

XR16C2852
2.97V TO 5.5V DUAL UART WITH 128-BYTE FIFOS
xr
REV. 2.1.1
Pin Description
NAME
RXA
RTSA#
CTSA#
DTRA#
DSRA#
CDA#
RIA#
MFA#
44-PLCC
PIN #
39
36
40
37
41
42
43
35
TYPE
DESCRIPTION
I _{UART channel A Receive Data or infrared receive data. Normal receive data input}
must idleHIGH. The infrared receiver pulses typically idles LOW but can be inverted
by software control prior going in to the decoder, see MCR[6] and FCTR[2]. If this pin
is not used, tie it to VCC or pull it high via a 100k ohm resistor.
O UART channel A Request-to-Send (active low) or general purpose output. This output
must be asserted (LOW) prior to using auto RTS flow control, see EFR[6], MCR[1],
FCTR[1:0], EMSR[5:4] and IER[6]. For auto RS485 half-duplex direction control, see
FCTR[3]. If this output is not used, leave it unconnected.
I UART channel A Clear-to-Send (active low) or general purpose input. It can be used
for auto CTS flow control, see EFR[7], and IER[7]. This input should be connected to
VCC when not used.
O UART channel A Data-Terminal-Ready (active low) or general purpose output. If this
output is not used, leave it unconnected.
I UART channel A Data-Set-Ready (active low) or general purpose input. This input
should be connected to VCC when not used.
I _{UART channel A Carrier-Detect (active low) or general purpose input. This input}
should be connected to VCC when not used.
I _{UART channel A Ring-Indicator (active low) or general purpose input. This input}
should be connected to VCC when not used.
O Multi-Function Output Channel A. This output pin can function as the OP2A#, BAUD-
OUTA#, or RXRDYA# pin. One of these output signal functions can be selected by
the user programmable bits 1-2 of the Alternate Function Register (AFR). These sig-
nal functions are described as follows:
1) OP2A# - When OP2A# (active low) is selected, the MF# pin is LOW when MCR bit-
3 is set to a logic 1 (see MCR bit-3). MCR bit-3 defaults to a logic 0 condition after a
reset or power-up.
2) BAUDOUTA# - When BAUDOUTA# function is selected, the 16X Baud rate clock
output is available at this pin.
3) RXRDYA# - RXRDYA# (active low) is intended for monitoring DMA data transfers.
See Table 2 on page 9 for more details.
TXB
RXB
If this output is not used, leave it unconnected.
26
O _{UART channel B Transmit Data or infrared encoder data. Standard transmit and}
receive interface is enabled when MCR[6] = 0. In this mode, the TX signal will be
HIGH during reset or idle (no data). Infrared IrDA transmit and receive interface is
enabled when MCR[6] = 1. In the Infrared mode, the inactive state (no data) for the
Infrared encoder/decoder interface is LOW. If this output is not used, leave it uncon-
nected.
25
I _{UART channel B Receive Data or infrared receive data. Normal receive data input}
must idle HIGH. The infrared receiver pulses typically idles LOW but can be inverted
by software control prior going in to the decoder, see MCR[6] and FCTR[2]. If this pin
is not used, tie it to VCC or pull it high via a 100k ohm resistor.
4